From ffa802f5834e0af5663bd902c7ff07789dd85069 Mon Sep 17 00:00:00 2001
From: Nikita Smith <nikita.smith@epicgames.com>
Date: Wed, 1 May 2024 16:54:15 -0700
Subject: [PATCH] codeview: inline binary annot format and decode helpers

---
 src/codeview/codeview.c | 68 +++++++++++++++++++++++++++++++++++++++++
 src/codeview/codeview.h | 58 +++++++++++++++++++++++++++--------
 2 files changed, 113 insertions(+), 13 deletions(-)

diff --git a/src/codeview/codeview.c b/src/codeview/codeview.c
index ad1b528e..06b2d2c8 100644
--- a/src/codeview/codeview.c
+++ b/src/codeview/codeview.c
@@ -165,6 +165,74 @@ cv_f64_from_numeric(CV_NumericParsed *num){
   return(result);
 }
 
+////////////////////////////////
+//~ Inline Binary Annotation Helpers
+
+internal U64
+cv_decode_inline_annot_u32(String8 data, U64 offset, U32 *out_value)
+{
+  U32 value;
+
+  U64 cursor = offset;
+
+  U8 header = 0;
+  cursor += str8_deserial_read_struct(data, cursor, &header);
+
+  // 1 byte
+  if((header & 0x80) == 0)
+  {
+    value = header;
+  }
+  // 2 bytes
+  else if((header & 0xC0) == 0x80)
+  {
+    Assert(cursor + sizeof(U8) * 2 <= data.size);
+    U8 second_byte;
+    cursor += str8_deserial_read_struct(data, cursor, &second_byte);
+    value = ((header & 0x3F) << 8) | second_byte;
+  }
+  // 4 bytes
+  else if((header & 0xE0) == 0xC0)
+  {
+    Assert(cursor + sizeof(U8) * 3 <= data.size);
+    U8 second_byte, third_byte, fourth_byte;
+    cursor += str8_deserial_read_struct(data, cursor, &second_byte);
+    cursor += str8_deserial_read_struct(data, cursor, &third_byte);
+    cursor += str8_deserial_read_struct(data, cursor, &fourth_byte);
+    value = (((U32)header & 0x1F) << 24) | ((U32)second_byte << 16) | ((U32)third_byte << 8) | (U32)fourth_byte;
+  }
+  // bad encode
+  else if((header & 0xE0) == 0xE0)
+  {
+    value = max_U32;
+  }
+
+  *out_value = value;
+
+  U64 read_size = cursor - offset;
+  return read_size;
+}
+
+internal U64
+cv_decode_inline_annot_s32(String8 data, U64 offset, S32 *out_value)
+{
+  U32 value;
+
+  U64 read_size = cv_decode_inline_annot_u32(data, offset, &value);
+
+  if(value & 1)
+  {
+    value = -(value >> 1);
+  }
+  else
+  {
+    value = value >> 1;
+  }
+
+  *out_value = (S32)value;
+
+  return read_size;
+}
 
 ////////////////////////////////
 //~ CodeView Sym Parser Functions
diff --git a/src/codeview/codeview.h b/src/codeview/codeview.h
index a037bee2..ff9f348e 100644
--- a/src/codeview/codeview.h
+++ b/src/codeview/codeview.h
@@ -1761,13 +1761,51 @@ struct CV_SymBuildInfo
 
 //- (SymKind: INLINESITE)
 
+typedef U32 CV_InlineBinaryAnnotaiton;
+typedef enum CV_InlineBinaryAnnotationenum
+{
+  CV_InlineBinaryAnnotation_Null,
+  CV_InlineBinaryAnnotation_CodeOffset,
+  CV_InlineBinaryAnnotation_ChangeCodeOffsetBase,
+  CV_InlineBinaryAnnotation_ChangeCodeOffset,
+  CV_InlineBinaryAnnotation_ChangeCodeLength,
+  CV_InlineBinaryAnnotation_ChnageFile,
+  CV_InlineBinaryAnnotation_ChangeLineOffset,
+  CV_InlineBinaryAnnotation_ChnageLineEndDelta,
+  CV_InlineBinaryAnnotation_ChangeRangeKind,
+  CV_InlineBinaryAnnotation_ChangeColumnStart,
+  CV_InlineBinaryAnnotation_ChangeColumnEndDelta,
+  CV_InlineBinaryAnnotation_ChangeCodeOffsetAndLineOffset,
+  CV_InlineBinaryAnnotation_ChangeCodeLengthAndCodeOffset,
+  CV_InlineBinaryAnnotaiton_ChangeColumnEnd
+};
+
+typedef U32 CV_InlineRangeKind;
+typedef enum CV_InlnineRangeKindEnum
+{
+  CV_InlineRangeKind_Expr,
+  CV_InlineRangeKind_Stmt
+};
+
 typedef struct CV_SymInlineSite CV_SymInlineSite;
 struct CV_SymInlineSite
 {
   U32 parent;
   U32 end;
   CV_ItemId inlinee;
-  // CV_BinaryAnnotation annotations (rest of data)
+  // U8 annotations[] (rest of data)
+};
+
+//- (SymKind: INLINESITE2)
+
+typedef struct CV_SymInlineSite2 CV_SymInlineSite2;
+struct CV_SymInlineSite2
+{
+  U32 parent_off;
+  U32 end_off;
+  CV_ItemId inlinee;
+  U32 invocations;
+  // U8 annotations[] (rest of data)
 };
 
 //- (SymKind: INLINESITE_END) (empty)
@@ -1835,18 +1873,6 @@ struct CV_SymPogoInfo
   U32 post_inline_static_inst_count;
 };
 
-//- (SymKind: INLINESITE2)
-
-typedef struct CV_SymInlineSite2 CV_SymInlineSite2;
-struct CV_SymInlineSite2
-{
-  U32 parent_off;
-  U32 end_off;
-  CV_ItemId inlinee;
-  U32 invocations;
-  // CV_BinaryAnnotation annotations (rest of data)
-};
-
 //- (SymKind: HEAPALLOCSITE)
 
 typedef struct CV_SymHeapAllocSite CV_SymHeapAllocSite;
@@ -2905,6 +2931,12 @@ internal U64              cv_u64_from_numeric(CV_NumericParsed *num);
 internal S64              cv_s64_from_numeric(CV_NumericParsed *num);
 internal F64              cv_f64_from_numeric(CV_NumericParsed *num);
 
+////////////////////////////////
+//~ Inline Binary Annotation Helpers
+
+internal U64 cv_decode_inline_annot_u32(String8 data, U64 offset, U32 *out_value);
+internal U64 cv_decode_inline_annot_s32(String8 data, U64 offset, S32 *out_value);
+
 ////////////////////////////////
 //~ CodeView Sym/Leaf Parser Functions